Emergency 087 1318706
Southview Veterinary Hospital - Small Animal 052 6121429
Southview Veterinary Hospital - Farm 052 6121429

Congestive Heart Failure

What Is Congestive Heart Failure?

Congestive Heart Failure (CHF) can be caused by many different heart conditions in dogs and cats. It represents an advanced stage of heart disease. Mitral valve disease, DCM, ARVC and HCM are some of
the most common causes, but there are dozens of other possible diseases that may result in CHF.

CHF occurs when heart disease causes a decline in the pumping ability of the heart. Blood cannot move forward as it usually does, so it builds up behind the problem area (congestion). Pressure builds up in the blood vessels of the lungs if the left heart is failing, and in the blood vessels of the body cavities if the right heart is failing. When the pressure builds up high enough, fluid will leak out of the blood vessels. Fluid leaks into the lungs (pulmonary oedema) with left heart failure and into the abdomen or chest cavity with right heart failure.

In the lungs, this fluid fills the sacs where normally only air should be. The pet has to take more breaths to absorb the amount of oxygen they need. This increases the breathing rate and effort, which may be subtle at first, but can become quickly life-threatening.

Clinical Signs/Symptoms

The main clinical sign of CHF is a change in breathing; especially an increase in breathing effort or rate. You may also see panting, wheezing or coughing. Breathing changes may be subtle at first, but serious respiratory distress can occur without warning in some cases. Therefore it’s always very important to investigate even mild breathing changes.

Lethargy or weakness is also common, and animals may tire quickly during exercise. Collapsing or fainting can be an issue for some pets.

The abdomen may become enlarged in right heart failure.

Pets may have a murmur or arrhythmia detected on clinical exam; however, in some cases no murmur is present even with severe heart disease.


Diagnosis of CHF is usually made with chest x-rays and/or echocardiography.

Chest x-rays allow visualisation of fluid on or around the lungs, and can also differentiate non-cardiac
causes of breathing problems in your pet.

Echocardiography is where ultrasound is used to examine the heart, and is also known as an “echo” or a heart scan. Echo allows the underlying heart condition to be identified accurately and stage of disease to be assessed. Ultrasound can also be used to detect fluid in the abdomen.

In some cases, an ECG may be recommended to check for arrhythmias (abnormal electrical activity in the heart).

Because these tests are minimally invasive, diagnosis is usually a simple, stress free experience for most pets.

Treatment of CHF

Diuretics are the most important medication for pets with CHF. These are drugs which remove excess fluid from the lungs or abdomen. They are very important to keep your pet breathing comfortably and to avoid a respiratory crisis from occurring.

Other drugs may be used to improve your pet’s heart contractility, slow down heart remodelling, control arrhythmias, prevent clots, or to help blood pressure. Specific treatment will depend on what the underlying condition is, and what stage of disease your pet is in.

In the case of right heart failure, your pet may also need excess fluid drained directly from their abdomen or chest.

It is very important to monitor pets on heart medication, in case adjustments are needed to their drug dosages. You may be asked to monitor sleeping respiratory rate (SRR), as well as attend the clinic for repeat check-ups at certain intervals, especially if there has been a recent change to your pet’s medication.

Return to Cardiology